Mazda MX-5 NA silhouetteMX-5 NA

LIGHTING SYSTEM — Troubleshooting

T-59prose procedure
Continued from T-58

Troubleshooting

Symptom: Stoplights do not operate (all).

Stoplights do not operate (all)

  1. 1
    Check STOP 15A fuse in the fuse box. If the fuse is burned, replace it. Check and repair the wire harness, if necessary. If the fuse is OK, go to Step 2.
    Illustration of the FUSE BOX showing the fuse layout with the STOP 15A fuse highlighted by an arrow at the bottom-right of the fuse box. Label 05U0TX-120.
    05U0TX-120
  2. 2
    Measure the voltage at the following terminal-wires of the stoplight switch connector.
    Illustration of the brake pedal and stoplight switch with its connector, showing pin labels (W/G) and (G) on the stoplight switch connector. Label 05U0TX-121.
    05U0TX-121
  3. 3
    Check the stoplight bulbs. If a bulb is burned, replace it. If the bulbs are OK, go to Step 4.
    Illustration showing the STOPLIGHT bulb (rear stoplight assembly with bulb) on the left and the HIGH-MOUNT STOPLIGHT assembly on the right. Label 05U0TX-122.
    05U0TX-122
  4. 4
    Measure the voltage at the following terminal-wires of the right and left stoplight connectors.
    Illustration showing voltmeter (V) probes connected to the stoplight harness; the connector at upper right is labeled with pins (B) and (G). Label 05U0TX-123.
    05U0TX-123

Step 2 — Stoplight switch connector voltage check

Constant
Wire(W/G)
Voltage12V
ActionNext check wire (G)
Constant
Wire(W/G)
Voltage0V
ActionRepair wire (W/G) (STOP 15A fuse—Stoplight switch)
Brake pedal depressed
Wire(G)
Voltage12V
ActionGo to Step 3
Brake pedal depressed
Wire(G)
Voltage0V
ActionCheck stoplight switch

Step 4 — Stoplight connector voltage check

Brake pedal depressed
Wire(G)
Voltage12V
ActionNext check wire (B)
Brake pedal depressed
Wire(G)
Voltage0V
ActionRepair wire (G) (Stoplight switch—Stoplight)
Brake pedal depressed
Wire(B)
Voltage12V
ActionRepair ground wire (B)
Brake pedal depressed
Wire(B)
Voltage0V
ActionCheck for poor connection of connectors
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